As described in U.S. Pat. No. 7,731,576 to CNH America LLC, which is incorporated by reference herein in its entirety, axially arranged rotary threshing or separating systems have long been in use in agricultural combines for threshing crops to separate grain from crop residue, also referred to as material other than grain (MOG). Such axially arranged systems typically include at least one cylindrical rotor rotated within a concave or cage, with the rotor and surrounding concave being oriented so as to extend forwardly to rearwardly within the combine.
In operation, crop material is fed or directed into a circumferential passage between the rotor and the concave, hereinafter referred to as a rotor residue passage, and is carried rearwardly along a generally helical path in such passage by the rotation of the rotor as grain is threshed from the crop material. The flow of crop residue or MOG remaining between the rotor and concave after threshing is typically discharged or expelled by the rotating rotor at a rear or downstream end of the rotor and the rotor residue passage in a generally downward, or a downward and sidewardly, direction in what is a continuation of the helical path of movement of the crop residue within the rotor residue passage between the rotor and concave.
The flow is typically discharged into a discharge opening at the downstream end of the rotor and into a further passage, hereinafter referred to as a discharge passage or discharge chute, that extends downwardly and somewhat rearwardly into a crop residue distribution system located below and rearwardly of the rear end of the threshing system, which crop residue distribution system typically includes a laterally disposed rotary beater or chopper that beats or chops the crop residue into smaller pieces and propels the resulting chopped crop residue rearwardly within a rear end of the combine for either discharge from the combine through a rear opening onto a field or introduction into a residue spreader apparatus, which residue spreader apparatus may include a further chopper and/or spreader, mounted on the rear end and operable for spreading the residue over a swath of a field.
Due to the nature of operation of the threshing rotor, the design of such rotor and concave, and the helical movement of the crop residue within the rotor residue passage, the resulting flow of crop residue from the rotor residue passage into the discharge opening is often greater on the downward sweep side of the rotor than on the upward sweep side, as a consequence of which an uneven flow of crop residue is presented across the width of the discharge opening and so introduced into the beater or chopper. Such uneven input flow has typically, in the past, resulted in inefficient operation of the beater or chopper, uneven wear of components of the beater or chopper, and poor material conveyance from the beater or chopper to the residue spreader apparatus at the rear of the harvester.
Since the flow of crop residue as introduced into the beater or chopper is often considerably heavier at one side of the beater or chopper, the crop mat introduced into the beater or chopper is often too thick for the beater or chopper to effectively handle, as a consequence of which the chop quality of the residue discharged from the beater or chopper is often less than desirable. Because the components of the beater or chopper which are associated with the side of the beater or chopper that experiences such heavier flow are subjected to greater abuse, they wear more quickly, thus degrading the performance of the beater or chopper over time, especially on the side handling the heavier flow. As a consequence, the output flow of residue from the beater or chopper often exhibits both uneven chop quality and uneven distribution across the width of the beater or chopper, with the heavier concentration of the poorly chopped residue remaining concentrated along the side of heavier flow from the threshing rotor as the crop residue proceeds toward the residue spreader. Such uneven flow across the width of the beater or chopper poses difficulties for the combine users.
Combine users desire, in many instances, when the crop residue is to be spread in a swath over a field, that the crop residue be distributed evenly or uniformly over the swath. Uniform distribution is desirable for a number of reasons. Included among such reasons are that uneven crop residue distribution on a field can lead to temperature and moisture gradients detrimental to even growth of future crops on the field, uneven distribution can make it difficult for crops to utilize nutrients, and uneven distribution can impact the effectiveness of agricultural chemicals. In addition, the existence of large discontinuities of spread crop residue can lead to plugging and other functional problems when such discontinuities are encountered by tillage and/or planting equipment.
It has been recognized that one factor that affects the ability of a residue spreader to distribute crop residue evenly or uniformly over a field is the transverse or side to side evenness of crop residue inflow into the residue spreader. However, the side to side uniformity of the infeed to the residue spreader is directly related to the side to side uniformity of the output flow from the beater or chopper, and since such output flow is recognized to be a function of the side to side distribution of crop residue infeed into the beater or chopper from the threshing system, it is therefore desirable to be able to effect a relatively uniform distribution of crop residue across the width of the beater or chopper, or at least to be able to more evenly distribute the flow being discharged from the threshing rotor.
In light of the foregoing considerations, several devices and structures have been developed to try to improve and better distribute the flow of crop residue from axially arranged threshing systems into crop residue distribution systems, including constructions such as are disclosed U.S. Pat. No. 7,731,576 (the '576 Patent).
FIG. 1 of the '576 Patent, reproduced herein as FIG. 1, depicts a representative agricultural combine 20 that includes an axially arranged threshing system 22 and a crop residue distribution system 24 that includes a beater or chopper 46.
As can be generally and essentially observed from a review and study of FIGS. 1-3 of the '576 Patent, which are reproduced herein as FIGS. 1-3, respectively, threshing system 22 is axially arranged in that it includes a cylindrical rotor 28 conventionally supported and rotatable in a predetermined direction, with arrow A in FIG. 2 denoting a typical clockwise, or forward, rotation, about a rotational axis 30 therethrough and within a concave 32, for conveying a flow of crop material in a helical flow path through a space 34 extending circumferentially around an outer cylindrical surface 35 of rotor 28 and an inner circumferential surface of concave 32. As the crop material is moved through space 34, the crop, such as grain, legumes, or the like, will be loosened and separated from crop residue such as husk and pods, and carried away therefrom in the well-known conventional manner.
As may be observed from FIG. 3, the crop residue will continue along a helical path through space 34, and will be discharged or expelled therefrom into a discharge opening and through a discharge passage 36, which essentially comprises an extension of space 34 at the downstream end of rotor 28. Some of the flow expelled through discharge passage 36 will tend to be directed to flow generally downwardly along internal side 38 (FIG. 2) of the rotor discharge housing, while some portions of the flow will be directed and/or be carried by rotating rotor 28 and momentum, in a transverse direction, denoted by arrow C in FIG. 2, toward an opposite internal side of combine 20, and will eventually flow downwardly toward the beater or chopper 46 of crop residue distribution system 24, such as denoted by arrows C2.
The consistency of the flow of crop residue, volume thereof, and extent or pattern thereof, will typically vary, and be a function of a variety of conditions, including, but not limited to, a speed of rotation in direction A of rotor 28, crop type, plant maturity, moisture content, and weather conditions. As an example, rotor speeds can vary between just a few hundred rpm and over a thousand rpm. Wheat and other small grains will typically have relatively small crop residue components, whereas other grains, such as corn, will typically have larger components, such as thick stalk segments, cob fragments, and large leaves. Typically, as observable in FIG. 2, the downward flow of crop residue will be more to a right hand side of a front-to-rear extending vertical centerline 40 of both threshing system 22 and crop residue distribution system 24. The sideward extent of such typical downward flow is represented by extent D in FIG. 2, and is generally bounded on the left hand side by a line 42 extending generally downwardly on the left of centerline 40, and on the right hand side by a line 44 extending generally downwardly from internal side 38, the sideward or transverse location of line 42 and thus the transverse extent D of the downward flow varying as a function of one or more of the above conditions and/or parameters.
Here, it should be noted that crop residue distribution system 24 will typically include a rotary device, such as a beater or chopper 46 (see FIG. 3), rotatable in a direction E above a concave pan 48. Chopper 46 typically rotates at a rapid speed, so as to be capable of accelerating and propelling a flow of crop residue rearwardly within the confines of the rear end of combine 20, as generally denoted by arrows F. Such rearward flow is typically guided and directed by internal panels or shields, generally denoted by shields 50 (FIG. 1), so as to either flow into a crop residue chopper and/or spreader, such as chopper/spreader 26, hereinafter referred to as a spreader, or through a rear opening so as to be deposited directly onto a field.
Threshing system 22 includes a rigid rotor discharge deflector apparatus 52 for deflecting crop residue more uniformly across the width of beater or chopper 46. Rigid rotor discharge deflector apparatus 52 includes rigidly braced upper ramp portion 53 that extends into the path of at least a portion of the crop residue flow B. More particularly, upper ramp portion 53 extends into the crop residue flow so that at least portions of that crop residue flow which would flow along or close to side 38, will instead impinge or strike upper ramp portion 53 and be deflected downwardly thereby, as denoted by arrows B and B1 in FIG. 2.
The downwardly directed crop residue flow, as illustrated by representative arrow B1, will be transversely shifted or moved in a transverse direction in the discharge passage, that is, more to the left of internal side 38 in such figures, depending on the transverse position and the slope of upper ramp portion 53.
Addressing FIG. 2 more particularly, the transverse movement or shifting of downwardly directed flow B1 causes a corresponding transverse shift of other portions of the downwardly directed flow in the transverse direction, as illustrated by arrows C1. As described in the '576 Patent, it was found that the overall transverse extent of the downward flow of crop residue, denoted by extent D1, extending between lines 54 and 56, could be transversely moved or shifted by use of a deflector apparatus, such as the rigid rotor discharge deflector 52 and its braced upper ramp portion 53, in the path of portions of flow B in the vicinity of internal side 38 of the combine.
Thus, for a combine including a crop residue distribution system, such as system 24 including a rotary chopper 46, the transverse position or location of crop residue inflow could be adjusted, for example, to be more uniformly distributed with a vertical centerline of the distribution system, such as centerline 40, which is a joint centerline of rotor 28 of threshing system 22 and chopper 46 of distribution system 24, as illustrated by the location of the center of transverse extent D1 in FIG. 2.
As viewed in FIGS. 2 and 3, in its normal, forward operation, rotor 28 is rotated in a clockwise direction, making the right side of concave 32 the downward swept side and the left hand side of concave 32 the upward swept side. Discharge deflector apparatus 52, with its upper ramp portion 53, is shown mounted within the discharge passage 36 at the downstream end of rotor 28 at approximately the level of the axis 30 of rotor 28 at its downstream end, with upper ramp portion 53 extending into the flow of crop residue to intercept at least a portion of the crop residue as the crop residue is helically expelled from the upper portion of rotor residue passage 34 on the downward swept side of rotor 28 and to deflect the intercepted flow so that crop residue will be more uniformly introduced to chopper 46.
Opportunities remain for improving the performance of the above-described threshing system 22. For instance, since discharge deflector 52 is fixed in position, the trajectory of the discharge cannot be adjusted to conform to variable crop conditions, thereby leading to non-uniform material delivery across the width of the chopper 46 in certain conditions. It was also found that deflector 52 recompressed the crop residue or MOG causing the compressed MOG to travel further around the rotor 28 than expected, thereby leading to non-uniform material delivery across the length of the chopper 46. Recompression of the MOG also requires the application of more power to the rotor 28, which is disadvantageous from a power efficiency perspective. Lastly, deflector 52 could be damaged if not retracted before operating rotor 28 in a reverse rotational direction because MOG travelling in an opposite direction could deform the fixed deflector 52.